"""Record of phased-in incompatible language changes.Each line is of the form: FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease "," CompilerFlag ")"where, normally, OptionalRelease < MandatoryRelease, and both are 5-tuplesof the same form as sys.version_info: (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int PY_MINOR_VERSION, # the 1; an int PY_MICRO_VERSION, # the 0; an int PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string PY_RELEASE_SERIAL # the 3; an int )OptionalRelease records the first release in which from __future__ import FeatureNamewas accepted.In the case of MandatoryReleases that have not yet occurred,MandatoryRelease predicts the release in which the feature will become partof the language.Else MandatoryRelease records when the feature became part of the language;in releases at or after that, modules no longer need from __future__ import FeatureNameto use the feature in question, but may continue to use such imports.MandatoryRelease may also be None, meaning that a planned feature gotdropped.Instances of class _Feature have two corresponding methods,.getOptionalRelease() and .getMandatoryRelease().CompilerFlag is the (bitfield) flag that should be passed in the fourthargument to the builtin function compile() to enable the feature indynamically compiled code. This flag is stored in the .compiler_flagattribute on _Future instances. These values must match the appropriate#defines of CO_xxx flags in Include/compile.h.No feature line is ever to be deleted from this file."""all_feature_names=["nested_scopes","generators","division","absolute_import","with_statement","print_function","unicode_literals",]__all__=["all_feature_names"]+all_feature_names# The CO_xxx symbols are defined here under the same names used by# compile.h, so that an editor search will find them here. However,# they're not exported in __all__, because they don't really belong to# this module.CO_NESTED=0x0010# nested_scopesCO_GENERATOR_ALLOWED=0# generators (obsolete, was 0x1000)CO_FUTURE_DIVISION=0x2000# divisionCO_FUTURE_ABSOLUTE_IMPORT=0x4000# perform absolute imports by defaultCO_FUTURE_WITH_STATEMENT=0x8000# with statementCO_FUTURE_PRINT_FUNCTION=0x10000# print functionCO_FUTURE_UNICODE_LITERALS=0x20000# unicode string literalsclass_Feature:def__init__(self,optionalRelease,mandatoryRelease,compiler_flag):self.optional=optionalReleaseself.mandatory=mandatoryReleaseself.compiler_flag=compiler_flagdefgetOptionalRelease(self):"""Return first release in which this feature was recognized. This is a 5-tuple, of the same form as sys.version_info. """returnself.optionaldefgetMandatoryRelease(self):"""Return release in which this feature will become mandatory. This is a 5-tuple, of the same form as sys.version_info, or, if the feature was dropped, is None. """returnself.mandatorydef__repr__(self):return"_Feature"+repr((self.optional,self.mandatory,self.compiler_flag))nested_scopes=_Feature((2,1,0,"beta",1),(2,2,0,"alpha",0),CO_NESTED)generators=_Feature((2,2,0,"alpha",1),(2,3,0,"final",0),CO_GENERATOR_ALLOWED)division=_Feature((2,2,0,"alpha",2),(3,0,0,"alpha",0),CO_FUTURE_DIVISION)absolute_import=_Feature((2,5,0,"alpha",1),(2,7,0,"alpha",0),CO_FUTURE_ABSOLUTE_IMPORT)with_statement=_Feature((2,5,0,"alpha",1),(2,6,0,"alpha",0),CO_FUTURE_WITH_STATEMENT)print_function=_Feature((2,6,0,"alpha",2),(3,0,0,"alpha",0),CO_FUTURE_PRINT_FUNCTION)unicode_literals=_Feature((2,6,0,"alpha",2),(3,0,0,"alpha",0),CO_FUTURE_UNICODE_LITERALS)